Manufacture of crystallized zinc sulphide



Patented Nov. 3, 1925. I

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To all whom it may concern: Be it known that we, Gnonens nn Hiinou- VILLE and PIERRE PIPEREAUT, citizens of the French Republic, and. residents of Longwy, Meurthe et 'Moselle, and Paris, France, have invented certain new and useful Improvementsin the Manufacture of Crystallized Zinc Sulphide, of which the following is a specification.

Our present invention relates tothe manufacture of crystallized zinc sulphide and has for its object to provide adry" process of manufacturing crystallized zinc sulphide, that is onewhich does not require either precipitation or washing and which is carried into practice by simple fusion.

' a presence of an excess of hydrogen sulphide Primarily our improved process consists.

in calcining solid zinc salts containing oxygen within a gas-tight oven, through which a current ofhydrogen sulphide gas is caused to pass either alone or a mixture of hydrogen sulphide and sulphur dioxide.

If sulphate of zinc isused and the same is for instance incompletely dry and heated in a closed oven, such salt will produce sulphur dioxide and sulphuricacid, which in will produce the following reactions:

so,+2H,s=3s+2 ,o 1) c and These are the principal reactions, and be I sides a very small quantiy 'of products of the thionic series will be obtained.

The reaction 1) may be in part produced artificially by suit-ably injecting additional sulphurous gas. a l As will be seen from the'above reaction, hydrogensulphide gas need not be dried to enter into reaction,

Until a certain point one maythink that i the zinc sulphate will be finally convert-ed to zinc sulphide by the action of sulphur in a vapour condition on said compound, althou hv sulphur will not be used its initial con ition in our present process. Our improved manufacture may be represented, if-sulphate Application flied January 2, 1924. Serial No. 684,058.

uamrrao'runn or CBYSTALLIZED zmc suLrnmE.

following reactions and varying between 250. C. and. the red heat.

produced in a closed oven. at a temperature- The reaction 3) corresponds to the case of an excess of H 8 gas. In fact it will be' seen that sulphur will be distilled at the outagitate the mass, as at the time of production of SOJ-I and-SO, the above mentioned.

reactions Will take lace. Therefore it wil be seen that: according zinc sulphide and-either sulphur or sulphur I dioxideas a by-product, in cases where the zinc salt is sulphate ofzinc.

Such sulphur dioxide w1ll' not be mixed with air, be liquefied and discharged either it may v in this conditionor after being diluted with air to the working conditions, we may produce used in the manufacture of sulphuric acid.

n Thus it will'be seen that if it is supposed that in the manufacture of zincsul hlde we use zinc blende, sulphuric acid and ydro n v sulphidearejonly-intermediate bodies which; I are immediately'broughtback again-into the That is 'to sayzinc -6 ycle of operations.

ende or impure zinc sulphide will be converted to pure white, amorphous o'r'crsytallized through} the agency of-- 1. Sulphuric acid upon ;z'1nc,'blende for the production of sulphate of zinc, and

2.v Hydrogen sulphide acting on'such sul- Q phate said gas being-produced by the action of diluted sulphurlc acid on sodium sul- Iphide for instance, and sulphate of sodium thus produced being reduced by coal, producingsodiumsulphide again, or utilizing residual sulphur from the principal process for producing sodium sulphide.

Zinc sulphlde manufactured according to our improved process may be obtained, ac-

cording to the temperature, in an amorphous semi-crystallized or completely crystallized condition, by raising the temperature and prolonging the current of hydrogen sulphidegas.

Having now fully described our said invention, what we claim and desire to secure by Letters Patent, is:

1. A dry process of manufacturing crystallized zinc sulphide, which consists in cans-c oxide in a dry condition to act on a solid oxygenated zinc compound at a temperature of from 250 C- to red heat, substantially at set forth.

3. A dry process of manufacturing crystallized zinc sulphide, which consists in causing hydrogen sulphide gas and sulphur dioxide in a moist condition to act on solid oxygenated zinc salts at a temperature of 250 C.-to red heat, substantially as set forth.

4. A dry process of manufacturing crystallized zinc sulphide, which consists in causing hydrogen sulphide gas and sulphur dioxide to act on sulphate of zinc at a temperature of 250 C: to red heat, substantially as set forth.

In testimony whereof -we have hereunto our hands.

GEORGES DE HEDOUVILLE. PIERRE PIPEREAUT. 

